Microwave crosslinking of polyacrylic compositions containing dextrin
and their applications as molding sands binders
Polimery 2009, No 7/8, 507
Three polymeric compositions being the mixtures of aqueous solutions of either poly(acrylic acid) or poly(sodium acrylate) or sodium salt of maleic acid/acrylic acid copolymer and dextrin (biopolymer) were elaborated. These compositions were crosslinked by microwave radiation and then the changes of chemical structures, caused by radiation, were evaluated by FT-IR method (Table 1-3, Fig. 1-4). Molding sands were prepared from high-silica sand as a matrix and non-crosslinked polymer compositions mentioned above as the binders. Molding sand hardening was carried out under microwave radiation. Compression strength (Rcu) of hardened molding sands was investigated (Fig. 5). The molding sands containing poly(acrylic acid) + dextrin composition (composition I) show the best compression strength. The morphology of crosslinked material prepared with use of composition I was characterized by SEM method (Fig. 6).
Key words: polyacrylates, biopolymers, dextrin, molding sand, binder, crosslinking, microwaves, chemical structure, compression strength
Microwave crosslinking of polyacrylic compositions containing dextrin and their applications as molding sands binders